Computer data is vital to today's organizations. Enterprise storage systems are the type of storage systems that an enterprise uses to store data that needs a high level of availability and reliability. Commercial or consumer storage systems are those that are used by consumers or for general commercial use. In general, the requirements of an enterprise storage system, and differences from a consumer type system, can be expressed with respect to 4 attributes, Performance, Reliability, Durability, and Workload.
In general, the performance for an enterprise storage system needs to be the “best in class” under a given workload. Conversely, a consumer or commercial performance needs only be “good enough” for a particular application. Generally, an enterprise storage system needs a very low failure rate. In comparison, the failure rate for commercial or consumer memory is rarely tracked. With respect to durability, the enterprise system typically needs to withstand 5 years of use whereas a commercial system may require 3 years of use. Further, during those working conditions, the enterprise system must be available for 24 hours a day for seven days a week whereas a commercial system may only need to be available for 8 hours a day for 5 days a week.
In an effort to increase performance, both systems have begun to move to a storage type called flash which can provide higher reliability and quicker access times than traditional magnetic disk based storage. The quicker access times and higher reliability, due to no moving parts, comes at a cost of a fixed number of possible writes to the flash memory. In general, there are 2 types of flash memory, SLC flash and MLC flash. Both types of flash have much faster access rates than typical disk based hard drives. However, both types of flash are also more expensive. As well, both types of flash have a limited number of writes until they fail and are no longer usable for storage. For example, SLC flash may fail after approximately 100,000 writes where MLC flash may fail after a number of rights, for example 10,000 writes, which may be about 1/10 the number of writes as SLC. In addition, SLC flash can be written to about twice as fast as MLC flash and is about 3 times more expensive to produce.